Fuel injector for diesel engines and the like



March 21, 1944. v w. J. SCOTT ETAL I 2,344,555

FUEL INJECTOR FOR DIESEL ENGINES AND THE LIKE Filed June 50, 1941' 4 Sheets-Sheet 1 March 21, 1944. w J SCOTT r AL I 2,344,565

FUEL INJECTOR FOR DIESEL ENGINES AND THE LIKE Filed June 50, 1941- q 4 Sheets-Sheet 2 Az'romx M 1944- w. J. scoTT. ETAI.

FUEL INJECTOR FOR DIESEL ENGINES AND THE LIKE Filed June 50, 1941 4jShe ets-Sheet 3 March 21, 1944. J, SC T ET A 2,344,565

FUEL INJECTOR FOR DIESEL ENGINES AND THE LIKE Filed June 30, 1941 4 Sh eets-S heet 4 Patented Mar. 21,- .1944

' OFFICE FUEL INJECTOR FOR DIESEL ENGINES Wallace J. Scott and Wallace 1. sum, Jr.,

White lalns, N. Y.

Application June so, 1941, serial No. 400,530

- 4-Claims. (01. 103-41) The object of the present invention is to provide a Diesel fuel injector of great simplicity and easeof adjustment, the characteristic being that only'one lifting cam is necessary for operation of the injector for either single cylinder or multiple cylinder engines, and the construction provides an ease of control for all conditions, which is not found in existing types of apparatus for the purpose.

The invention will be described with reference to the accompanying drawings, in which:

Figure 1 is a sectional elevation illustrating an embodiment of'the invention, the section being parallel with the face of the single actuating cam for the several injector plungers.

Figure 2 is a sectional elevation of the said embodiment extended at substantially right angles to the view shown in Figure 1.

Figure 3 is a top plan view broken away on the line 3-3, Figure 2.

Figure 4-is a horizontal section on the line 4-4, i ure 1.

Figure 5 is a sectional elevation broken away atits base showing modified forms of the device.

Figure 6 is a view in horizontal section on the line 6-8, Figure 5.

Referring to the'drawings and Figures 1 and '3, it will be seen that the embodiment illustrated is adapted for a four cylinder engine or one having a lesser number of cylinders. A cylindrical housing employing two sections i and I1, is employed, a packing ring 2 being interposed between the sections and the sections being held in rigid connection by bolts or screws 3. The upper section is provided with a plurality of annularly arranged bores, of a number corresponding with the number of cylinders in the engine for which the injector is designed. Each of these annularly arranged bores is preferably formed with a lower area of lesser diameter and an upper area of greater diameter, as shown more particularly in Figures 1 and 2. Referring to the latter figures, it will be seen that in the bore of lesser diameter is inserted an injector cylinder sleeve 4 having a top flange 4:1: which rests upon the lower face or base of the bore area having larger diameter. Threaded in the larger bore is a closure plug 5 which serves as a valve housing. Each sleeve preferably extends downwardly into a chamber of housing section I and is formed with a shoulder and receiving area for a spiral spring I, the shoulder being provided by reduc ng the lower end of said sleeve 4. Die lower end .of the spring bears against an intermediate shouldered area la:

of an injection plunger I, the latter preferably carrying at its lower end a plurality of rollers 8. In the present embodiment these rollers are three in number.

The injector plunger I, in each 'case, is'preferably formed with .a longitudinal keyway which may extend upwardly into the shouldered area Ix. The key 9 may be carried by the injector plunger so as to slide in the channel formed in a disk-plate I 0 carried by the lower housing section II: or the key may be fixed to said plate.

In the present embodiment the lower housing section I: is formed with a depending neck which may fit within an aperture formed in a bracket or-other suitable support for the device such as that indicated at H, Figure 1.

Within housing section I and mounted upon the bearing ring I2 is a rotary cam carrier I! which is formed with a vertical channel at i3: to receive and permit axial movement of injector cam [4, the latter being keyed to a shaft I! which is mounted in a bearing aperture formed in rotary cam carrier l3. The inner end of shaft l5 carries an eccentrically disposed crank pin I51: which enters a horizontal channelwa'y at the top of a vertically movable rod l6 mounted within the sleeve-like depending portion Hxzc o1! the rotary cam carrier.

A pin i1 is so carried by rod l6 that the ends of the pin enter apertures in a channel ring i8.

- Referring to Figure 1 it will be seen that channel ring #8 receives a crank stud 20 carried eccentrically of the shaft I9 which may be oscillated in a bearing sleeve 2i fitted within an aperture formed in housing section la, the outer and projected end of shaft i9 receiving a lever arm 22 which may be connected by means of a link 23 with a hand or foot control, the operation of which will impart endwise .inovement to rod IS and thereby change th position of cam l4 to increase or reduce its degree of lift relatively to the injection plungers I.

In the embodiment shown there is secured to the lower projected end of sleeve-like extension l3xz: of the rotary cam carrier. a gear 24 which may be driven by a gear 25 operated from the Diesel engine to which the injector will be applied. When, however, the injector is applied to a two-cycle engine the rotary cam carrier may be directly driven from the crank shaft to the v engine.

at 42.1! in injector cylinder 4 which port is in register with a duct 8:: in housing section I and which is in communication with the main oil feed bore 3.1:: of said housing section, the latter having threaded therein a nipple It for connection with an oil line under pressure.

.At its reduced oil-receiving section each injector plunger I is formed with an oil duct 1!- leading upwardly to a ball check chamber of I larger diameter and in which is disposed the ball check 21 engaged by a spring 2! at the top of which is a threaded holding plug 2! apertured for passage of oil.

The closure plug is axially bored in each case. to receive a discharge and line relief valve 30 which normally closes a port at ll leading to and from the injector cylinder, valve 30 being engaged at its top by spring 31 below a threaded nipple 3! leading, in each case, to one of the cylinders of the Diesel engine by means of a pipe connection (not shown) Within the axial bore of valve ll is a ball check 34 engaged by a spiral spring ll held in position by a small inverted plug 36. In the operation of the embodiment illustrated in Figures 1 to 4 inelusive, rotation of shaft it and the rotary cam carrier II in which it is mounted will carry cam it into successive engagement with the injection plungers which are spaced equally in circular arrangement, and, at the same time, the channel ring II which is secured to the shaft or vertically movable rod II will in its rotation remain in operative relationship with stud 20 with the cam adjusting means, so that the operative throw of the cam may be adjusted at will during the operation of the injector.

As each injector plunger is driven upwardly in an active stroke, the ball check 21 will be closed by the pressure imposed upon Lhe oil immediately above the plunger. This pressure will raise valve II (which may be longitudinally fluted) and the fuel oil charge will be forced aroimd valv 30 and upwardly through the conduit leading to the ap- Droprlate combustion cylinder of the Diesel ensine. When the cam leaves the plunger the latter will descend and valve 80 will drop into closed position.

When valve I. is dropped into closed position and pressure in the injector cylinderis relieved y the downward movement of the plunger, the th pressure in the line above said valve is immediately relieved, said pressure causing ball check It to open the internal passageway of the valve for such purpose. Any oil in the line above valve II in excess of that needed for line pressure relief will not be sucked back into the 'oil injection chamber of the injector cylinder, because immediately upon relief of excess pressure in the line and the balancing of the pressures above and below'valve Iii, check 84 will be moved to closed position by spring 3!.

Cam ll withits quick-acting adjusting means acts as a throttle to, control the speed of the en- Bine. Thus link 28 may be connected to a foot pedal or hand lever, as will be understood without further explanation.

The disk ll, resting on an annular shoulder provided by the lower casing section is: may be given a rotary adjustment by means of the lever rod II. uponioosening nut II threaded on the rod, inasmuch as the rod passes through an elongated slot in the housing is: as indicated at H,

Figure 6, and thus timing can be controlled. The amount of lifting motion given by the cam II depends on how much of the cam projects above the top surface of the cam-retainin disk II and adjustment in the height of the cam is effected by rotating shaft ii, on which the cam is mounted.

this rotation being effected byengagement of the walls of the channel in shaft It with stud ll: carried eccentrically of shaft II at the inner end thereof. Shaft ii is encircled by peripherally channeled collar "ll into the channel of which projects stud 20 eccentrically mounted on shaft I! carrying lever 22 which, in turn. is connected to pull rod or link 23. The adjustments of the disk II and cam carrier ll may be eil'ected during the rotation of the cam carrier. Collar II is held against rotation on shaft it by a pin I1 passing through the latter and through elongated slots formed at opposite points in the sleeve-like hub depending from cam retaining disk II.

In the modified embodiment illustrated in Figure 5, all of the elements from and including the rotary cam carrier and the cam carried thereby, including adjusting means for the cam to the drive gear 24, are the same as in the preceding embodiment and like reference characters are employed. Also all of the elements of the first embodiment which are carried by the upper housing 1 are employed for the modification illustrated in Figure 5 and like reference characters are employed. There has been added by the modification a characteristic made possible by theaddition of a few extra elements. With the use of these added elements the injector is capable of universal use, inasmuch as it can be used for a wide range of engine cylinder displacements.

Referring to Figure 5, it will be seen that immediately below housing I there has been interposed a housing ring 39 carrying a heavy plate 40 having apertures receiving a plurality of rocker arms 4 I, one for each injector plunger, the rocker arms being pivoted on pivot pins 42. Immediately below housing ring 38, xcept for a packing ring 43, is a second housing ring It carrying an axially adjustable disk 45 in which are mounted a plurality of actuator rods 48, one for each rocker arm. As indicated in Figure 6, housing ring I is formed with a wide slot through which passes a lever rod 41 secured to disk 45, by means of which the actuator rods may b adjusted simultaneously toward and from the axis of movement of the appropriate rocker arm in each case.

Rotatably carried by housing is: at its top is a disk 48 carrying a plurality of actuator rods ll, each lying under and in contact with an appropriate one of the actuator rods 46. Each actuator rod 48 carries at its lower end three rollers N, the center one of which directly receives the stroke of cam It in the revolutions of the rotary cam carrier II, and those at each side straddling the cam slot in the cam carrier.

By the adjustment of disk 45 the rock": arm actuator rods 48 will effect fuel control, lefuel being injected as to each cylinder of th engine when disk ll is adjusted to carry actuator rods N away from the pivot points of the rocker arms,

, adjustment of the said disk 45 in a reverse direc- By means of the modification, an adjustment is provided which gives the equivalent of placing small or larger injector cylinders and plungers in a fuel injector of standard type.

By mounting the cam ll at the periphery of the rotary cam'carrier the injector cylinders and push rods may be arranged regularly instead of parallel as in the embodiments illustrated. This arrangement wil1 be useful when the injector is applied to radial engines, particularly high-speed radial engines customarily employedin aircraft.

When so arranged, th injector would add-very little to the depth of the radial engine and could be mounted coaxially therewith so as to be driven directly from the engine crank shaft whenever the engine is of two-cycle form. Also the high pressure oilioutlet of each injectorcylinder would be immediately'adjacent the cylinder or the engine to which it is appropriate and the high pressure fuel lines would be short and all equally distant with respect to the cylinders of the engine.

It will be understood that various modifications I may be made in the form and arrangement of the elements comprising the embodiments-above il1ustrated,'in addition to those just above described. As an example, means may be provided for rotating the rocker arm carrier 40 to relatively adjust the positions of the plungers and rocker arms for increased or decreased movement of the plungers to supplement or eliminate the adjustment-provided for carrier 45.

Having described our invention, what we claim and desire to secure by Letters lows: i

1. In injectors for Diesel engines, a plurality of injector cylinders arranged in an annular path,

means for leading fuel oil to the injector cylinders, tin-actuating cam, a. rotary carrier for said actuating cam,'means for rotating the carrier to ing said than during the rotation of the cam carsaid means prising a second shaft mounted in and coaxially of the cam carrier,-

means intermediate the second shaft and the cam nel ring for imparting endwisemovement-tothe said second shaft.

3. In injectors 01 Diesel engines, a plurality of injector cylinders arranged in an annular path, means for leading fuel oil to the cylinders, a plurality of sectional plungers, the sections of each plunger being relatively movable into and out of coaxial relationship, a rotary carrier for an actuating cam, an actuating cam on said carrier. means for simultaneously moving one section of each of the plungers into or out of coaxial arrangement with the second section, and means so Patent, is' as folbring the cam-into successive engagement'with the plungers, a shaft for the cam and rotatably carried by the cam carrier, and means'for' rotatior-rotating the carrier to. bring the cam into successive engagement with the piungers.

4. In injectors for Diesel engines constructed in accordance with claim 3, in which one section of each plunger is mounted within one of the Y injector cylinders and the second'section of each plunger is disposed exteriorly ofvan appropriate injector cylinder. the means for relatively moving the sections of,.the plungers comprising a member receiving said second plunger sections and supporting them for endwise movement.

warmer: J. soon." I WALLACE J. sco'rr, JR. 

